What is the recommended rate for the replacement of free water deficit in the first 24 hours?

The recommended rate for the replacement of free water deficit in the first 24 hours is half of the calculated free water deficit. This approach is based on the principle of careful rehydration to avoid complications associated with rapid correction, such as osmotic demyelination syndrome, particularly in cases of hyponatremia.

Free water deficit is typically calculated when assessing a patient who is hypernatremic, and it represents the amount of water that needs to be replaced to restore normal serum sodium levels. By administering half of the calculated deficit over the first 24 hours, healthcare providers can effectively manage hydration while monitoring the patient's clinical status and laboratory values.

The remaining half can then be given over the next 24 to 48 hours, allowing for gradual correction. This tiered approach ensures that the body can adapt to changes in serum sodium concentration without the adverse effects that can occur with more rapid changes.